Process for preparing hexaorganoditin compounds

ABSTRACT

THIS INVENTION IS A METHOD FOR PREPARING COMPOUNDS OF THE FORMULA R3SNSNR3 COMPRISING PYROLYZING A TRIORGANOTIN FORMATE OF THE FORMULA   (R-)3-SN-OOC-H   WHERE R IS A HYDROCARBON SELECTED FROM THE GROUP CONSISTING OF ALKYL, ALKENYL, ARALKYL, AND CYCLOALKYL RADICALS, AND SEPARATING R3SNSNR3.

United States Patent Office 3,652,618 Patented Mar. 28, 1972 3,652,618 PROCESS FOR PREPARING HEXAORGANODITIN COMPOUNDS Gerald H. Reifenberg, Hightstown, and William J. Considine, Somerset, N.J., assignors to M & T Chemicals Inc., New York, N.Y. No Drawing. Filed Nov. 4, 1968, Ser. No. 773,329 Int. Cl. C07f 7/22 U.S. Cl. 260-429.7 4 Claims ABSTRACT OF THE DISCLOSURE This invention is a method for preparing compounds of the formula R SnSnR comprising pyrolyzing a triorganotin formate of the formula RaSnO 011 wherein R is a hydrocarbon selected from the group consisting of alkyl, alkenyl, aralkyl, and cycloalkyl radicals, and separating R SnSnR This invention relates to a novel process for producing organotin compounds.

This invention is a method for preparing compounds of the formula R SnSnR comprising pyrolyzing a triorganotin formate of the formula R SnO (in wherein R is a hydrocarbon selected from the group consisting of alkyl, alkenyl, aralkyl, and cycloalkyl radicals, and separating R SnSnR According to another of its aspects, the method of this invention for preparing compounds R SnSnR comprises heating a first moiety of triorganotin formate of the formula B38110 EH to form triorganotin hydride of the formula R SnH O B33110 in R is a hydrocarbon radical preferably selected from the group consisting of alkyl, alkenyl, cycloalkyl, and aralkyl including such radicals when inertly substituted. When R is alkyl, it may typically be straight chain alkyl or branched alkyl, including ethyl, n-propyl, isopropyl, nbutyl, isobutyl, sec-butyl, n-amyl, neopentyl, isoamyl, nhexyl, isohexyl, heptyls, octyls, decyls, dodecyls, tetradecyl, octadecyl, etc. Preferred alkyl includes lower alkyl, i.e. having less than about 9 carbon atoms, i.e. octyls and lower. When R is alkenyl, it may typically be vinyl, allyl, 1-propenyl, methallyl, buten-l-yl, buten-2-yl, penten-l-yl, hexenyl, heptenyl, octenyl, decenyl, dodecenyl, tetradecenyl, octadecenyl, etc. When R is cycloalkyl, it may typically be c'yclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, etc. When R is aral'kyl, it may typically be benzyl, B-phenylethyl, y-phenylpropyl, fl-phenylpropyl,

etc. R may be inertly substituted, e.g. may bear a nonreactive substituent such as alkyl, cycloalkyl, aralkyl, alkenyl, ether, ester, etc. Typically substituted alkyls include 2-ethoxyethyl, carboethoxymethyl, etc. Substituted alkenyls include 'y-phenylpropenyl, etc. Substituted cycloalkyls include 4-methylcyclohexyl, etc. Inertly substituted aralkyl includes p-phenylbenzyl, p-methylbenzyl, etc.

In the practice of this invention it is desirable to use an inert diluent. Typical inert diluents include inert hydrocarbons such as benzene, toluene, etc., and aliphatic hydrocarbons including hexane, heptane, octane, etc. Preferably the solvent is one which has boiling point at atmospheric pressure of at least about C. and typically 100 C. to 200 C.

The reaction of this invention is preferably carried out under inert atmosphere, e.g. nitrogen, since the products, e.g. hydrides and ditins may be oxidized by oxygen.

In carrying out the novel reaction of this invention, the raw material is maintained at C. to 200 C. for 2 hours to 12 hours.

In the practice of this invention the following reactions may occur 0 1 12.5.0011 R SmH+ CO;

0 O I zSnH RaSnO OH aasusnm HCiOH Trialkyltin hydrides formed as intermediates in the practice of this invention include triethyltin hydride, trin-propyltin hydride, tri-isopropyltin hydride, tri-n-octyltin hydride, and tricyclohexyltin hydride.

At the completion of the reaction, after the by-products have been removed, the product may be separated and recovered by conventional means. When the product is present together with the diluent, the product, if insoluble in the diluent, may be filtered, washed, and further purified if desired. If the pure product is soluble in the diluent it may bes'eparated by distillation under reduced pressure.

For the purpose of giving those skilled in the art a better understanding of the invention, reference is made to the following examples.

EXAMPLE 1 Preparation of hexabutylditin Into a reaction vessel maintained under an atmosphere of nitrogen, 50.0 grams (0.15 mole) of tributyltin formate was introduced. The two-necked, 100 milliliter reaction vessel was fitted with a magnetic stirring bar, a water condenser, and a thermometer. The tributyltin formate was heated at temperatures ranging from 150 C. to 185 C. for 11.5 hours during which time a flow of nitrogen gas was maintained by the reaction vessel. At the end of 11.5 hours, the reaction mass exhibited a weight of 38.3 grams. Vapor phase chromatographic analysis of the product showed that the yield of hexabutylditin was 77.5% of the reaction mass, tributyltin formate was 10.4% of the reaction mass, tetrabutyltin was 5.2% and tributyltin hydride was 6.9%.

EXAMPLE 2 Preparation of hexapropylditin 1 Into a reaction vessel maintained under an atmosphere of nitrogen, 29.3 grams (0.1 mole) of tripropyltin formate was introduced. The tripropyltin formate was heated at a temperature of 120 C., initially, agitated, and incrementally, increased to a temperature of 180 C. The reaction time was 21.5 hours during which time a flow of nitrogen was continuously maintained to the reaction vessel. The entire reaction mass was distilled under vacuum using a fractionatiu g head. The distillate exhibited a weight of 48.3 grams. Vapor phase chromatographic analysis of the product showed that the yield of hexapropylditin was 42.0% of the distillate.

EXAMPLE 3 Preparation of hexabutylditin Into a reaction vessel maintained under an atmosphere of nitrogen was introduced 11.6 grams (0.04 mole) of tributyltin hydride and 13.4 grams (0.04 mole) of tributyltin formate. The reaction mixture was heated at a temperature of 145 C. to 165 C. for 5.5 hours. Vapor phase chromatographic analysis of the product showed that the yield of hexabutylditin was 54.5% of the reaction mass. Tributyltin formate was 33.8% of the reaction mass and tributyltin hydride was 5.3

EXAMPLE 4 Preparation of hexapropylditin Into the reaction vessel maintained under an atmosphere of nitrogen was introduced 10.0 grams (0.4 mole) of tripropyltin hydride and 11.7 grams (0.04 mole) of tripropyltin formate. The procedure of Example 3 was followed to obtain a yield of 46.4% of hexapropylditin. Vapor phase chromatographic analysis indicated that tripropyltin formate comprises 41.4% of the reaction mass and propyltin hydride comprised 3.8%

The products of the process of this invention are also useful as catalysts for various reactions. The compounds of this invention are useful as catalysts for a polymerization of ethylene and propylene. For example, they are also used in the polymerization of diene hydrocarbons .4 having conjugated double bonds in the presence of cobalt or nickel compounds and aluminum halides, e.g. cobalt naphthenate and aluminum.

Although this invention has been illustrated by reference to specific examples, numerous changes and modifications thereof which clearly fall within the scope of the invention will be apparent to those skilled in the art.

We claim:

1. A method for preparing compounds of the formula R SnSnR comprising pyrolyzing at a temperature of from C. to 200 C., a triorganotin formate of the formula 0 n sno ("1H wherein R is a hydrocarbon selected from the group consisting of alkyl, alkenyl, aralkyl, and cycloalkyl radicals, maintaining said reaction temperature for at least 2 hours and separating R SnSnR 2. The process of claim 1 wherein R exhibits less than 9 carbon atoms.

3. The process of claim 1 wherein said triorganotin formate is tripropyltin formate.

4. The process of claim 1 wherein said triorganotin formate is tributyltin formate.

References Cited UNITED STATES PATENTS 3,439,010 4/1969 Itami et al 260429.7

DELBERT E. GANTZ, Primary Examiner W. F. W. BELLAMY, Assistant Examiner 

